Should doctors prescribe exercise?

“Although the data vary by different cancer types, there is a consistent trend suggesting that moderate daily exercise has a beneficial effect on preventing certain cancers. If you are a reasonably healthy adult, your should exercise regularly.” 

Let’s look at the relationship of exercise and selected cancers. The American Society of Clinical Oncology (ASCO) has done a nice job of summarizing:

Breast Cancer

While the amount of risk reduction varies among studies (20-80%), most suggest that 30 to 60 minutes of moderate to high-intensity exercise per day lowers breast cancer risk. Women who are physically active throughout their life appear to benefit the most, but those who increase physical activity after menopause also fare better than inactive women.1

Colon Cancer

Research suggests that people who increase their physical activity can lower the chance of developing colon cancer by 30 to 40% relative to sedentary adults.1,2 A decrease in colon cancer risk can be achieved regardless of body mass index (BMI) and people who are most active benefit the most. There is insufficient evidence of a protective effect of physical activity on the risk of rectal cancer (a protective effect was seen in some case-control studies, but not in cohort studies).3

Endometrial, Lung and Ovarian Cancer

A handful of studies have suggested that women who are physically active have a 20-40% reduced risk of endometrial cancer compared to those who don’t exercise.1 Higher levels of physical activity seem to also protect against lung cancer (up to 20% reduction in risk), particularly among men.1Although less consistent, research suggests that physical activity possibly reduces the risk of ovarian and prostate cancer.

What about Other Cancers?

While observational data on the benefits of exercise for prevention of the types of cancers listed above are fairly consistent, evidence of the effects of exercise on prevention of any other type of cancer either is either insufficient or inconsistent.2,4

Prostate Cancer

Prostate cancer is one disease in which the data are not consistent, however prostate cancer is a heterogeneous disease and risk factor associations for total non-aggressive disease are different from aggressive / lethal disease. Most population based studies show similar findings, with little effect of exercise on overall incidence of prostate cancer but lower risk of aggressive prostate cancers for those with the highest levels of VIGOROUS activity (rather than any type of activity). In the Health Professionals Follow-up Study men 65 years or older who engaged in vigorous physical activity, such as running, jogging, biking, swimming or tennis at least three hours per week  had a 67% lower risk of advanced prostate cancer and 74% lower risk of fatal prostate cancer.5

Conflicting data for other malignancies

For example, one recent study found no association between physical activity and risk of developing gastric, rectal, pancreatic, bladder, testicular, kidney and hematological cancers.4 In contrast, a pooled analysis of data from prospective trials with 1.4 million participants found that physical activity was linked to lower risk of 13 cancers: esophageal, lung, kidney, gastric, endometrial, myeloid leukemia, myeloma, colon, head and neck, rectal, bladder, and breast.6Interestingly, leisure-time physical activity was associated with a higher risk of melanoma (presumably due to time spent outdoors) and prostate cancer, although it is not clear from these data whether that association was with nonaggressive or aggressive prostate cancer.

While we wait for confirmation and clarity on the role of exercise in preventing all the 200+ types of cancer – should doctors prescribe exercise? The answer is simple: yes, because evidence of the protective role of exercise is already strong for some of the most common cancers.

References

  1. Lee I, Oguma Y. Physical activity. In: Schottenfeld D, Fraumeni JF, editors. Cancer Epidemiology and Prevention. 3rd ed. New York: Oxford University Press, 2006.
  2. Slattery, ML. Physical activity and colorectal cancer. Sports Medicine 2004; 34(4): 239–252.
  3. Pham NM, et al. Physical activity and colorectal cancer risk: an evaluation based on a systematic review of epidemiologic evidence among the Japanese population. Jpn J Clin Oncol. 2012 Jan;42(1):2-13.
  4. Friedenreich CM, Neilson HK, Lynch BM. Eur J Cancer. State of the epidemiological evidence on physical activity and cancer prevention. 2010 Sep;46(14):2593-604.
  5. Giovannucci E, Liu Y, Leitzmann MF, et al. A prospective study of physical activity and incident and fatal prostate cancer. Arch Intern Med. 2005; 165(9):1005-1010.
  6. Moore SC, Lee IM, Weiderpass E, et al. Association of Leisure-Time Physical Activity With Risk of 26 Types of Cancer in 1.44 Million Adults. JAMA Intern Med. 2016 Jun 1;176(6):816-25.
  7. http://www.asco.org/about-asco/press-center/asco-resources-media/cancer-perspectives/should-cancer-doctors-prescribe?et_cid=38723632&et_rid=463715101&linkid=Read+more

I’m Dr. Michael Hunter. Of course, the disclaimer: Do not begin an exercise program without input from an appropriate medical professional. Many can simply start with a brisk walk for 30 minutes daily, 5 days per week. Have a wonderful day!

Fit Body at 40 May Keep Brain Bright at 60

What You Need to Know: People who are fit in their 40s seem to retain more brain volume two decades later and also perform better on decision-making tests.

The Study:

  • Just over 1,270 people underwent exercise treadmill testing in the 1970s, when their average age was 41. In their 60s, the participants underwent MRI brain scans and mental performance tests.
  • Those at midlife who had experienced a greater increase in heart rate or diastolic blood pressure after a few minutes of low-intensity exercise on a treadmill — signs of lower fitness levels — had smaller brain volumes later in life. Higher heart rate and blood pressure during exercise are indications of lower overall fitness levels and can also damage small blood vessels in the brain, the study authors explained.
  • Similarly, those with larger increases in blood pressure levels during low-intensity exercise performed worse on a mental (“cognition”) test of decision-making ability in their 60s.

Every 7.1 mm Hg rise in diastolic blood pressure (the bottom number in a reading) and additional 8.3 beats per minute in heart rate over participants’ resting levels were equated with an additional half-year of brain aging.

“In elderly individuals, improvements in fitness have been shown to prevent brain aging over the short-term. But it has not been clear whether fitness throughout adulthood has an impact on brain aging. In particular, it has not been clear how longstanding (or short-lived) an impact midlife fitness might have on late-life cognition.”

Dr. Joseph Masdeu, director of neuroimaging and the Nantz National Alzheimer Center at Houston Methodist Neurological Institute in Texas, praised the study’s design, because data was collected over decades and not subject to misreporting of personal fitness levels. He and Spartano agreed that factors other than fitness may have influenced the findings, and that those with better diets and other lifestyle habits may also be more likely to experience better brain health at older ages.

“This study cannot prove causality, because it’s possible that people with brain changes making them more likely to get Alzheimer’s are going to be less prone to exercising,” Masdeu said. “You can’t prove that exercise is what did it.”

Spartano said she could not recommend an optimal level of fitness to achieve better brain aging based on the study results. But, people should strive for exercise “that will get the heart pumping every day,” Masdeu suggested.

“It’s hard to give a quantified amount of exercise,” he acknowledged. “We are not telling people to run marathons. It’s a good idea to do some aerobic exercise that gets the heart pumping, such as half an hour of walking every day, or going up several fl

The small print: The material presented herein is informational only, and is not designed to provide specific guidance for an individual. Please check with a valued health care provider with any questions or concerns. As for me, I am a Harvard- , Yale- and UPenn-educated radiation oncologist, and I practice in the Seattle, WA (USA) area. I feel genuinely privileged to be able to share with you. If you enjoyed today’s offering, please consider clicking the follow button at the bottom of this page.

Available now: Understand Colon Cancer in 60 Minutes; Understand Brain Glioma in 60 Minutes. Both can be found at the Apple Ibooks store. Coming Soon for iPad: Understand Breast Cancer in 60 Minutes; Understand Colon Cancer in 60 Minuteable now: Understand Colon Cancer in 60 Minutes; Understand Brain Glioma in 60 Minutes. Thank you.

Reference: http://consumer.healthday.com/fitness-information-14/misc-fitness-health-news-312/fit-body-at-40-keeps-brain-bright-at-60-study-697117.html

Doe Exercise Really Make You Smarter?

What You Need to Know: Recently, some scientists have begun to question whether the apparently beneficial effects of exercise on thinking might be a placebo effect. The benefits of aerobic exercise are not a placebo effect.

Background: Exercise seems to be good for the human brain, with many recent studies suggesting that regular exercise improves memory and thinking skills. Studying this issue is challenging, as there is no placebo for exercise and no way to blind people about whether they are exercising.

Study: An interesting new study asks whether the apparent cognitive benefits from exercise are real or just a placebo effect – that is, if we think we will be “smarter” after exercise, do our brains respond accordingly? Researchers at Florida State University (USA) came up with a clever way to evaluate this: They focused on expectations, on what people anticipate that exercise will do for thinking. If people’s expectations jibe closely with actual benefits, then at least some of the improvements are probably a result of a placebo effect (and not exercise).

Researchers asked half of the study population to estimate how much stretching and toning (three times per week) might improve various measures of thinking, including memory and multitasking. The other volunteers were asked the same questions, but about a regular walking program. In actual experiments, stretching and toning have little if any impact on cognitive skills. Walking, on the other hand, improves thinking. But the survey respondents believed the opposite, estimating that the stretching and toning program would be more beneficial for the mind than walking.

The results from the study suggest that the benefits of aerobic exercise are not a placebo effect. This study was small and involved a self-selected group of people who like completing online surveys. Still, the data suggest exercise really does change the brain and may improve thinking. We should now turn to 1) looking more closely, at a molecular level, at how exercise remodels the brain; and 2) get more of us to exercise. I’m Dr. Michael Hunter.

The small print: The material presented herein is informational only, and is not designed to provide specific guidance for an individual. Please check with a valued health care provider with any questions or concerns. As for me, I am a Harvard- , Yale- and UPenn-educated radiation oncologist, and I practice in the Seattle, WA (USA) area. I feel genuinely privileged to be able to share with you. If you enjoyed today’s offering, please consider clicking the follow button at the bottom of this page.

Available now: Understand Colon Cancer in 60 Minutes; Understand Brain Glioma in 60 Minutes. Both can be found at the Apple Ibooks store. Coming Soon for iPad: Understand Breast Cancer in 60 Minutes; Understand Colon Cancer in 60 Minute; Understand Colon Cancer in 60 Minutes; Understand Brain Glioma in 60 Minutes. Thank you.

Reference: NY Times 25 November 2014

Cut Your Risk of Breast Cancer Now

women walking exercise

What You Need to Know: This could be the simplest bit of health advice ever: Exercise reduces women’s risk of breast cancer, no matter what kind of exercise they do, how old they are, how much they weigh, or when they get started.

The Study: Researchers in France looked at studies that involved more than 4 million women around the world who participated in prospective studies from 1987 to 2013. They found that the more active a woman is, the better her odds of avoiding breast cancer. Women who were most active, with more than an hour a day of vigorous activity, got the most benefits, lowering their cancer risk by 12 percent.

But women weren’t as active saw reduced risk, too, notes Mathieu Boniol, research director at the Strathclyde Institute for Global Public Health in Lyon, France. More activity was better, but anything was better than nothing. He presented the data Thursday at the European Breast Cancer Conference in Glasgow.

“This decrease is the same whatever the country, whatever the age, whatever the menopausal status,” Boniol told Shots. And it didn’t matter if women were active in work, activities of daily living, or sports. “It’s very good news.

Women who were overweight or obese benefited a little less, but still lowered their risk by 10 percent overall.

And women who got moving after menopause also saw benefits from exercise.

“It’s not something to say, ‘Oh, I’ve never done sports why do that right now?’ ” Boniol says. “We now have evidence that it could still be beneficial. And it’s cheap. It’s a very cheap way to do prevention of breast cancer.”

My Take: Scientists don’t know why physical activity reduces breast cancer risk. There’s been speculation about exercise’s effect on hormones and inflammation, but no one knows for sure. Other studies have found breast cancer risk reductions as high as 25 percent from physical activity, but because of the huge number of women included in this analysis, the 12 percent reduction may be more accurate. So, no matter where you live, your weight, or your age, keep moving. Keep moving. I’m Dr. Michael Hunter.

The small print: The material presented herein is informational only, and is not designed to provide specific guidance for an individual. Please check with a valued health care provider with any questions or concerns. As for me, I am a Harvard- , Yale- and UPenn-educated radiation oncologist, and I practice in the Seattle, WA (USA) area. I feel genuinely privileged to be able to share with you. If you enjoyed today’s offering, please consider clicking the follow button at the bottom of this page.

Available now: Understand Colon Cancer in 60 Minutes; Understand Brain Glioma in 60 Minutes. Both can be found at the Apple Ibooks store. Coming Soon for iPad: Understand Breast Cancer in 60 Minutes; Understand Colon Cancer in 60 Minute; Understand Colon Cancer in 60 Minutes; Understand Brain Glioma in 60 Minutes. Thank you.

Reference: http://www.npr.org/blogs/health/2014/03/20/291894075/exercise-cuts-breast-cancer-risk-for-all-women-everywhere

Sports Reduces Breast Cancer Risk

Seniors jogging exercise on forest woods road

Practising sport for more than an hour day reduces the risk of contracting breast cancer, and this applies to women of any age and any weight, and also unaffected by geographical location, according to research presented to the 9th European Breast Cancer Conference (EBCC-9). Compared with the least active women, those with the highest level of physical activity reduced their risk of breast cancer by 12%, researchers say.

The Study: Professor Mathieu Boniol, Research Director at the International Prevention Research Institute, Lyon, France, recently reported the results of a meta-analysis (study of a group of studies) of 37 studies published between 1987 and 2013, representing over four million women. “These are all the studies looking at the relationship between physical exercise and breast cancer risk that have been published to date, so we are confident that the results of our analysis are robust,” he said.

The Evidence: Although the results varied according to tumour type, the overall message was encouraging, the researchers say. However, in women taking hormone replacement therapy (HRT), the protective effect of exercise seemed to be cancelled out. But increased awareness of the side effects of HRT means that its use is decreasing in a number of countries, and this means that the beneficial effects of activity will most likely grow in the years to come. “Whether or not this will be the case is an interesting question and deserves to be followed up at a later date,” Prof Boniol said.

Physical activity is known to have a protective role in other cancers, as well as in disorders such as cardiovascular disease. Although the mechanisms for its effect are unclear, the results are largely independent of body mass index (BMI), so the effect must be due to more than weight control. And the age at which sporting activity starts also appears to be immaterial; the researchers found no indication that breast cancer risk would decrease only when physical activity started at a young age.

“Adding breast cancer, including its aggressive types, to the list of diseases that can be prevented by physical activity should encourage the development of cities that foster sport by becoming bike and walk-friendly, the creation of new sports facilities, and the promotion of exercise through education campaigns,” said Prof Boniol. “This is a low cost, simple strategy to reduce the risk of a disease that currently has a very high cost, both to healthcare systems and to patients and their families. It is good news both for individuals and for policy makers.”

My Take: Women have a real impetus to increase their physical activity by even modest increments. This review comfirms that improvements in breast health can now be added to the other established health benefits of physical activity. So keep moving! I love for my patients to get a minimum of the equivalent of a brisk walk, 5 times per week. If you can do more, great. But even that small amount of additional activity can add years to your life, while potentially lowering your risk of heart attack, stroke, dementia, and cancer. I’m Dr. Michael Hunter.

The small print: The material presented herein is informational only, and is not designed to provide specific guidance for an individual. Please check with a valued health care provider with any questions or concerns. As for me, I am a Harvard- , Yale- and UPenn-educated radiation oncologist, and I practice in the Seattle, WA (USA) area. I feel genuinely privileged to be able to share with you. If you enjoyed today’s offering, please consider clicking the follow button at the bottom of this page.

Available now: Understand Colon Cancer in 60 Minutes; Understand Brain Glioma in 60 Minutes. Both can be found at the Apple Ibooks store. Coming Soon for iPad:  Understand Breast Cancer in 60 Minutes; Understand Colon Cancer in 60 Minute; Understand Colon Cancer in 60 Minutes; Understand Brain Glioma in 60 Minutes. Thank you.

Reference: The European CanCer Organisation (ECCO). “Regular physical activity reduces breast cancer risk irrespective of age.” ScienceDaily. ScienceDaily, 20 March 2014. <www.sciencedaily.com/releases/2014/03/140320100816.htm>.

Staying Physically Fit Keeps You Mentally Fit

happy man white male smiling elderly senior older

Today we turn to an unusual study that gauged participants’ fitness levels by measuring oxygen levels during strenuous exercise. The results suggest that being in good physical condition may help you to preserve memory and cognition over time.

Physical Fitness and Mental FitnessResearchers asked 1400 adults (ages 19 to 94) to walk, jog, or run on a treadmill until theory were out of breath. The amount of oxygen subjects inhaled and the amount of carbon dioxide they exhaled was carefully measured, allowing scientists to calculate their VO2max (maximal amount of oxygen used by the lungs during one minute of strenuous exercise). A higher VO2max generally indicated better health associated with better lung function.

Participants were tracked for up to 18 years following the treadmill test, and took periodic cognitive tests measuring such factors as memory and attention. Participants with lower VO2max scores showed significantly accelerated cognitive decline (compared with those who started out with better fitness scores).

My Take: Cariovascular fitness measured at a point in time may help predict levels of future memory function. I’m Dr. Michael Hunter.

The small print: The material presented herein is informational only, and is not designed to provide specific guidance for an individual. Please check with a valued health care provider with any questions or concerns. As for me, I am a Harvard- , Yale- and UPenn-educated radiation oncologist, and I practice in the Seattle, WA (USA) area. I feel genuinely privileged to be able to share with you. If you enjoyed today’s offering, please consider clicking the follow button at the bottom of this page.

Available now: Understand Colon Cancer in 60 Minutes; Understand Brain Glioma in 60 Minutes. Both can be found at the Apple Ibooks store. Coming Soon for iPad:  Understand Breast Cancer in 60 Minutes; Understand Colon Cancer in 60 Minute; Understand Colon Cancer in 60 Minutes; Understand Brain Glioma in 60 Minutes. Thank you.

References: The Journals of Gerontology: Series A (05 November 2013); Massachusetts General Hospital: Mind, Mood & Memory (February 2014)

Physical Activity Extends Lives of Cancer Survivors

exercise jogging mature older elderly man activity physical

Physical activity significantly extends the lives of male cancer survivors, a new study of 1,021 men has found.

During the period while the men were followed, those who expended more than 12,600 calories per week in physical activity were 48 percent less likely to die than those who burned fewer than 2,100 calories per week. Kathleen Y. Wolin, PhD, of Loyola University Chicago Stritch School of Medicine, is co-author of the study, published in the Journal of Physical Activity & Health, the official journal of the International Society for Physical Activity and Health.

Background: Many cancer survivors are living longer, due to earlier diagnosis and better treatment, and their numbers are increasing rapidly. “Thus physical activity should be actively promoted to such individuals to enhance longevity,” researchers concluded. There has been extensive research showing that among generally healthy, cancer-free populations, physical activity extends longevity. But there has been relatively little such research on physical activity among cancer survivors.

Study Design: Researchers examined data from the Harvard Alumni Health Study, an ongoing study of men who entered Harvard as undergraduates between 1916 and 1950. Researchers looked at 1,021 men (average age 71) who previously had been diagnosed with cancer. In questionnaires conducted in 1988, men reported their physical activities, including walking, stair-climbing and participation in sports and recreational activities. Their physical activities were updated in 1993, and the men were followed until 2008.

Results: Compared with men who expended fewer than 2,100 calories per week in physical activity, men who expended more than 12,600 calories per week were 48 percent less likely to die of any cause during the follow-up period. This finding was adjusted for age, smoking, body mass index, early parental mortality and dietary variables. (By comparison, a 176-pound man who walks briskly for 30 minutes a day, five days a week burns 4,200 calories.)

What You Need to Know: There were similar findings for mortality from cancer and cardiovascular disease: the most physically active cancer survivors were 38 percent less likely to die of cancer and 49 percent less likely to die of cardiovascular disease during the follow-up period. If you are able to do so, aim for a minimum of 30 minutes of the equivalent of a brisk walk at least 5 days per week. If your healthcare provider gives you clearance to do even more, this study suggests that you should do so. I’m Dr. Michael Hunter.

The small print: The material presented herein is informational only, and is not designed to provide specific guidance for an individual. Please check with a valued health care provider with any questions or concerns. As for me, I am a Harvard- , Yale- and UPenn-educated radiation oncologist, and I practice in the Seattle, WA (USA) area. I feel genuinely privileged to be able to share with you. If you enjoyed today’s offering, please consider clicking the follow button at the bottom of this page.

Available now: Understand Colon Cancer in 60 Minutes; Understand Brain Glioma in 60 Minutes. Both can be found at the Apple Ibooks store. Coming Soon for iPad:  Understand Breast Cancer in 60 Minutes; Understand Colon Cancer in 60 Minute; Understand Colon Cancer in 60 Minutes; Understand Brain Glioma in 60 Minutes. Thank you.

Reference: Loyola University Health System. “Physical activity significantly extends lives of cancer survivors.” ScienceDaily. ScienceDaily, 23 January 2014. <www.sciencedaily.com/releases/2014/01/140123124652.htm>.

Journal reference: I-Min Lee, Kathleen Y. Wolin, Sarah E. Freeman, Jacob Sattlemair, Howard D. Sesso. Physical Activity and Survival After Cancer Diagnosis in MenJournal of Physical Activity and Health, 2014; 11 (1): 85 DOI: 10.1123/jpah.2011-0257